Rock core drill head



June 5, 1934- J. H. HOWARD 1,961,362

ROCK CORE DRILL HEAD Filed May 18, 1931 M 17 f :W72 1? 49 T30 mounting aroller cutter Patented .lune 5, 1934Y UNETED STATES PATE Roon conn DRILLHEAD ysignor to Globe Los Nietos,

Application May 18, 1931, Serial No. 538,210

` 11 claims. (c1. s55-72) This invention relates to a Well drillingtool,

and relates more particularly to a rock core drill for use in connectionwith the rotary method of well drilling. It is a general object of thepres ent invention to provide a simple, practical, and effective drillhead or cutter head for a rock core drill.

An object of this invention is to provide a simple, sturdy drill head orcutter head for a core drill that embodies a plurality of rollercutters.

Another object of the invention is to provide a core drill' embodying acutter head of the character mentioned in which the roller cutters aredependably and eiectively mounted and are independently and detacliablycarried by the body or barrel or" the core drill. The cutter headprovided by the present invention includes a plurality of units or wingsin each oi which is mounted a cutter and each of which is independentlydetachable from the barrel or body of the drill.

t is another object of this invention to pro- -vide a core drill thatincludes inner roller cutters having cutting parts for acting on theformation at the bottom oi the well bore and end lcutting parts fortrimming and cutting the core.

A further object of the invention is to provide a novel and improvedmeans for rotatably on the cutting head of a core drill.

It is a further object of the invention to pro- Ivide a rock core drillof the character mentioned 'that provides means for effectively Washingeach cutter with the circulation fluid.

A further object or" the present invention is to provide a core catcherfor use in connection with a core drill that includes slips or grips forengaging the core that are operable to tightly grip the core upon thetool being withdrawn or pulled upwardly.

It is another object vof the-invention' to provide a core catching meansof the character mentioned in which the weight of the core operates tocause the slips to tightly and effectively grip and hold the core as thetool is being withdrawn from the well.

Other objects and features of the invention will be best and more fullyunderstood from the following detailed description of a typical form andapplication of the invention, throughout which description referencewill be had to the accompanying drawing, in which:

Fig. 1 is a side elevation of the core drill provided by the presentinvention, showing it carried on the lower end of a string of 4drillpipe and in operating position in a well bore. Fig. 2

Vis an enlarged vertical detailed sectional view of the lower portion ofthe tool. Fig.y 3 is a diagrammatic View of the lower end of the drillhead, illustrating the arrangement of the cutters. Figs. 4 and 5 aretransverse detailed sectional views taken as indicated by'lines 4 4 and5 5 respectively on Fig. 2. Fig.l 6 is a side elevation of the corecatcher provided by the present invention, showing it apart from theother parts of the tool, and showing certain parts in cross section;

The core drill provided by this invention includes, generally, an outerbarrel 10, an inner barrel or core retainer 11, a cutter head or body 12on the lower endof the outer barrel 10, a

plurality of segmental units or wings 13 removably attached to the head10, sets or series of cutters 14 and 15 carried by the wings 13, and acore catcher or core engaging means 16.

The outer barrel 10 is an elongated tubular member adapted to beattached to the lower end of a string of drill pipe P, or the like. Thebarrel 10 may be mounted on the lower end of the operating string in anysuitable manner, for example, it may be connected with the lower end ofthe string of pipe P through a drill collar 17. A sub or tubularconnecting member 18 is provided on the lower end of the outer barrel10. A socket 19 may be provided in the upper end of the connectingmember and the lower end of the barrel 10 may be screw-threaded into thesocket.

The inner barrel or core retainer 11 is arranged within the outer barrel10 and is provided to receive the core or sample of the formation. Thecore retainer 11 extends longitudinally and centrally'through the outerbarrel 1G, and is spaced from the inner walls of the barrel 10 toprovide an lannular fluid passage. In accordance with the commonpractice, the upper end of the core retainer 11 may be provided with asuitable relief valve or vent (not shown) to provide for thedisplacement of fluid during passage of the core into the barrel. Thecore retainer 11 extends downwardly through the connecting sub 18 and isconnected with the cutter head 12, as will be hereinafter described.

The head 12 is the main or body portion oi' the cutting assemblyprovided by the present invention and is an elongated tubular membercarried on the lower end of the sub 18. The head 12 is provided at itsupper end with a socket 20 for receiving a screw-threaded pin 21 on thelower end of the sub 18. 4The upper portion of the' head Ava 12 may beof the same external diameter as the sub 18. A threaded portion 22 isprovided on the lower end of the core retainer 11 to thread into theupper end portion of the opening 23 of the head. This connection of thecore retainer 11 with the head eiiectively centers the core retainer inthe tool and maintains it in a position where it is spaced from theinner walls oi the outer barrel 10 and the sub 13. An enlarged lower endportion 24 is provided on the head 12 to provide sufficient stoel; foreiectively carrying the cutter units 13. The enlarged portion 24 isprovided with a plurality of circumferentiallyspaced vertical grooves24a.

The units or wings 13 are individually mounted on the lower end of thehead 12 so as to be readily removable or replaceable as independentunits. The wings 13 are arcuate or segment shaped in their generalconfiguration, and may be alike in size and shape externally. Theassembly of the several wings 13 constitutes a contiguous sectionalannular structure on the lower end of the head 12. The opposite sides orvertical side surfaces 25 of the units are preferably radial toeiectively abut or co-operate with. one another. Vertical notches 25ZLare provided in the outer sides of the wings to register with thegrooves 24a to provide a plurality of passages for the returningcirculation fluid. The wings 13 may be of the same thickness or width asthe enlarged end portion V24 of the head, so as to be flush with theinner and outer sides of the head as illustrated throughout the drawing.

The means for removably attaching the units or wings 13 tothe lower endof the head 12 includes a pin 26 projecting from the upper end of eachwing 13. The pins 26 t or extend into spaced sockets 27 in the lower endof the head 12. The pins 26 and sockets 27 may be of any suitable crosssectional conguration, for example, they may be round, as illustrated inFig. 4 of the drawing. A projecting rib or flange 28 is provided on theupper end of each wing 13 at the base of its pin 26 to co-operate with aslot 29 in the lower end of the head to hold the wing against rotationor turning. Means is provided for holding the cutter units or wings 13against longitudinal displacement from the head 12. Locking pins 30 arepassed through horizontal or tangential openings 31 in the head andnotches 32 in the pins 26 to hold the pins against longitudinal movementin the openings 27. It will be apparent how the several cutter carryingunits or wings 13 may be individually removed from the head 12 forexchange or replacement.

Each of the wings 13 carries a cutter. The cutters 14 are the outercutters for making an annular out in the formation and for cutting thewell bore to the desired size for passing the core drill. The cutters 15are the inner cutters oi the bit and are provided to make an annular outwithin the cut made by the outer cutters 14 and to trim the core. Thecutters 14 and 15 are in the nature of rock or roller type cutters andmay be related to one another in various manners. In the particulararrangement illustrated in the drawing, there are three outer cutters 14and three inner cutters 15 interposed or spaced between the outercutters.

The outer cutters 14 may be carried by three symmetrically or equallyspaced wings 13. The cutters 14 may be truste-conical in their generalconguration and are provided at their exteriors or peripheries withcutting `parts or teeth. The

outer 4cutters 14 are rotatably mounted on pins 33 carried by the wings13 disposed in vertical planes radial relative to the centrallongitudinal axis o the drill, and are inclined upwardly and outwardly.In accordance with the broader principles of the invention, the pins 33may be secured to the wings 13 in any suitable manner. In the embodimentof the invention illustrated in the drawing, the pins 33 are welded inopenings or slots 34 provided in the lower ends of the units or wings13. The pins 33 may extend completely through the wings 13, and theirends may be ilush with the inner and outer sides of the wings. Openings35 are provided in the wings 13 to pass or carry the cutters 14 withsuitable clearance. The pins 33 may be hard faced and may be providedwith means for holding the cutters 14 against longitudlnal movement andfor taking the thrusts during operation, An annular radial flange 36 isprovided on each pin 33 to fit a groove 37 in an end of each cutter 14.The iianges 36 are provided to take the working or cutting end thrusts,and their inner sides may be beveled to co-operate with beveled innerwalls of the grooves 37. The inner walls of the recesses 37 and theinner sides of the flanges 36 may be pitched or tapered at any suitableangle relative to the longitudinal axis of the pins. Annular bushings 38are provided on the pins 33- to co-operate with or t in grooves 39formed in ends of the cutters 14. The cutters 14 project downwardly fromthe lower ends of the wings 13 so that their cutting parts act on theformation at the bottom of the well bore. The outer cutters 14 alsoproject outwardly beyond the outer sides of the wings 13 to engage theformation and cut the bore to the proper size to pass the core drill.

The inner cutters 15 may be carried by the units or wings 13 spacedbetween the wings carrying the outer cutters 14. The inner cutters 15may be similar, generally, to the outer cutters, i. e., they may beroller cutters of frusto-conical configuration. In accordance with theinvention, the inner cutters 15 may be mounted in the units 13 insubstantially the same manner as the outer cutters 14. The inner coretrimming cutters 15 are rotatably mounted on pins 40 inclined downwardlyand outwardly relative to the longitudinal center of the tool, The pins40 may be substantially radially disposed, and their inner and outerends 'may be flush with the interiors and exteriors of the wings 13.Like the pins 33, the pins 40 may be welded in openings or sockets 41 inthe lower ends of the wings 13. A thrust shoulder or flange 42 isprovided on each pin to co-operate with a groove in one end of eachcutter 15, while a bushing 43 may be provided on the pin to t into agroove in the opposite end of the cutter 15. Suitably shaped openings 44are provided in the wings 13 to carry the cutters 15.

The cutters 15 are mounted and proportioned so as to project downwardlybeyond the lower ends of the units 13 to act on the formation at thebottom of the well bore. Further, the cutters are mounted so that theirinner edges project inwardly beyond the inner walls of the units orwings 13. Suitable teeth or cutting parts are provided on theperipheries of the cutters 15 to engage the formation at the bottom ofthe bore. It is a feature of the present invention that cutting parts 45are provided on the inner ends of the cutters 15 to cut or trim the corethat is received by the core kbarrel 11. The cutters 15 may be mountedand proportioned and the cutting parts 45 may be formed so as to trimthe core the desired diameter to readilyf pass into the drill. It is tobe noted that the two sets of cutters 14 and 15 may be arranged asdescribed above so that their action on the formation at the bottom ofthe Well bore overlaps to make an annular cut without the formation ofirregularities or projections on the bottom of the bore.

In accordance with the invention, means is provided for dischargingcirculation fiuid downwardly onto each cutter 14 and 15. An annularrecess 46 is provided in the inner walls of the head l2 at the lower endof the socket 20. The recess 46 is in full communication with theannular space between the outer barrel 10 and the inner core retainerl1. A plurality of spaced longitu dinal openings 47 are provided in thehead 12 to extend downwardly from the annular recess 46 to the upperends of the openings 27. A vertical or longitudinal opening 48 isprovided in each unit or wing 13 to extend downwardly from the upper endof its pin 25 to the opening carrying the cutter. The openings 48 are inregister or communication with the openings 47 and discharge downwardlyinto the openings 35 and 44. It will be apparent how the circulationfluid is discharged downwardly onto the cutters 14 and 15 to effectivelywash them and remove any cuttings that may have accumulated on theircutting parts. rThe circulation fluiddischarged into the openings 35 and44 cannot strike against the core and, accordingly, does not wash out ordestroy the core. A free and continuous circulation of uid may bemaintained at all times to insure the effective operation of the cutters14 and 15.

In accordance with the broader aspects of the invention, any suitableform of core catcher may be employed in the tool. In the drawing, I haveillustrated an improved core catcher 16 for catching or gripping thecore within the drill. The core catching means 16 includes a ring 50freely slidable in the upper portion of the head opening 23. A pluralityof circumferentially spaced spring fingers 51 are provided on the ring50 to engage the core. The spring fingers 51 are in the nature of leafsprings and project upwardly from the ring 50 and normally project orbend inwardly toward the vertical center of the opening 23. The springngers 51 may be multiple or double, i. e., they may each consist of twoleaf springs having their upper ends bent inwardly and spaced apart toengage the core at vertically spaced points. The upper ends of thelongest spring fingers may be toothed or serrated to effectively gripthe core.

The core catching means 16 includes a plurality of slips or grips 52suspended from the ring 50. The grips 52 are arcuate in their generalconfiguration and are operable upon relative longitudinal movementbetween the core and the head 12 to tightly grip the core. The grips 52are suspended from the ring 50 by flexible bands or springs 53v rivetedor otherwise attached to the exterior of the ring and the exteriors ofthe grips. 'Ihe outer sides 54 of the grips are tapered or inclineddownwardly and inwardly to effectively cooperate with or slide on theinclined walls of the opening 23. The interiors or inner sides of thegrips 52 are roughened or provided with gripping parts to engage thecore. The several grips 52 may be interconnected by straps or bands 55loosely attached to their outer sides. The bands may be attached to thegrips by rivets or screws 56 slidable in slots 57 in the bands 55. Thebands connect the grips so that the grips are free to shift together ortoward one another when forced Y into gripping engagement with the core.

3 It is believed that the operation of the core drill provided by thepresent invention will be readily appparent from the foregoing detaileddescription. During drilling or operation, the inner and outer cuttersoperate to make an annular cut in the formation, leaving a cylindricalcore to be received by the core retainer ll. The inner cutters 15 act onthe formation at the bottom of the well bore and also trim or cut theexterior of the core as it passes into the opening provided by theannular assembly of wings 13. The two sets of cutters 14 and l5 operateto effectively form an annular cut without projections or irregularitieswhich might come into contact with the lower ends of the segmental wings13. The circulation fluid may be discharged downwardly through the toolat all times to pass downwardly through the openings 48 against thecutters 14 and 15 to effectively wash the cutters. During drilling thecore passes into the openings 23 and into the retainer l1, and the ngers51 are forced or pressed outwardly against the interior of the corebarrel. Passage of the core into the barrel causes the ring 50 to assumean up position where it is in engagement with the lower end of the coreretainer 11. After the desired amount of core has been obtained, thetool may be withdrawn from the well. Upon the tool or drill being drawnupwardly, the spring fingers 51 bite into the core so that the assemblyof the ring 50 and grips 52 remain stationary relative to the core.Upward movement of the head 12 relative to the segmental grips 52 causesthe inclined walls of the opening 23 to co-operate with the taperedexteriors of the grips to force the grips inwardly into tight holdingengagement with the core. The engagement or grip obtained by the grips52 on the core is sufficient to break or pull the core loose from theearth upon the continued upward movement of the tool. weight of the coreafter being broken loose is supported by the assembly of the springfingers and grips so that the grips 52 are maintained in a down positionwhere they are tightly forced against the coie to effectively carry thecore as the tool is withdrawn from the well bore. It is to be noted thatthe invention provides a simple and effective means for mounting rollercutters on the lower end of a core drill or barrel.

The several cutter carrying wings 13 may be leasily and quickly removedfor replacement, or the like, and are particularly simple andinexpensive of manufacture. The cutters 14 and 15 are dependably andeffectively mounted in the units 13. The inner cutters 15 in trimmingthe core insure the proper shaping and proportioning of the core as itis passed into the core barrel.

Having described only a typical preferred form of my invention, I do notwish to limit myself to the specific details set forth, but Wish toreserve to myself any changes or variations that may appear to thoseskilled in the art or fall within the scope of the following claims:

Having described my invention, I claim:

1. A head for a core body, a plurality of cutter carrying units, andmeans independently detachably mounting the units on the lower end ofthe body in positions where their sides are n abutment, the saidabutting sides of the units having grooves forming external fluidchannels in said assembly.

2. A head for a core drill including, a tubular body, a plurality ofunits detachably mounted on the lower end of the body and having their'sides It Will be noted that the drill including a tubular 4 in abutmentforming an annular assembly, and roller cutters rotatably carried by theunits.

3. A head for a core drill including, a tubular body, a plurality ofunits detachably mounted on the lower end of the body in edge to edgerelation and forming a contiguous segmental assembly, and a cuttercarried by each of the units.

4. A head for a core drill including, a tubular body, a plurality ofunits having their contiguous side faces in abutmentl to orm a segmentalassembly, parts on the units set in openings in an end of the head,means for removably holding the said parts in the openings, and cutterspermanently mounted in the units.

5. A head for a core drill including, a. tubular body, a plurality ofunits on the lower end of the body in side by side relation to form acontiguous segmental assembly, parts on the units set in openings in theend of the head, means for removably holding the said parts in theopenings, pins extending through openings in the units, and rollercutters rotatably mounted on the pins, the contiguous sides of the unitshaving registering grooves forming fluid passing channels in theexterior of the said assembly.

6. A head for a core drill including, a tubular body, a plurality ofunits independently and detachably mounted on the lower end of the bodyand having their adjoining side 'faces in abutment forming a segmentalassembly, and cutters rotatably mounted in the units to have end cuttingparts projecting inwardly from said assembly.

7. A head for a core drill including, a tubular body, a plurality ofunits independently detachably mounted on the lower end of the body, theunits having their adjoining side faces in abutment to form a contiguousannular assembly, and cutters rotatably mounted in the units to haveperipheral cutting parts projecting from the lower ends of the units andcutting parts projecting into the opening in said assembly.

8. A head for a core drill including, a tubular body, a plurality ofunits independently detachably mounted on the lower end of the body, theunits having their adjoining side faces in abutment to forni acontiguous annular assembly, a

roller cutter rotatably carried in one of the units to have cuttingparts projecting from the bottom of said assembly, and a roller cutterrotatably carried in another unit to have cutting parts projecting intothe opening in said assembly.

9. A head for a core drill including, a tubular body, a plurality ofunits independently detachably mounted on the lower end of the body inside by side relation to form a contiguous segmental assembly, a rollercutter rotatably carried in one of the units to have cutting partsprojecting from the bottom of said assembly, and a roller cutterrotatably carried in another unit to have peripheral cutting partsprojecting from the lower end of the assembly and cutting partsprojecting inwardly from said assembly.

10. A head for a core drill including, a tubular body, arcuate wings atthe lower end of the body, means for detachably mounting the wings onthe body in positions Where their side faces are in abutment to form anannular assembly, said means including, a projection on each wingiitting an opening in the body, and locking pins holding the projectionsin the openings, and a roller cutter rotatably mounted in an opening ineach wing, there being a uid passage in the body communicating with thesaid opening in the body, and a 4uid passage in each wing incommunication with the iirst mentioned uid passage and discharging intothe cutter carrying opening of the wing.

11. A core drill including, an outer barrel, an inner barrel within theouter barrel, there being an annular fluid passage between the twobarrels, a head mounted on the lower end of the outer barrel, aplurality of wings at the lower end of the head, means for independentlydetachably mounting the wings on the lower end of the head to have theirside faces in abutment and form a contiguous segmental assembly, androller cutters rotatably mounted in openings in the wings and projectingfrom the wings, there being spaced fluid openings in the headcommunicating with the said fluid openings and discharging into theopenings carrying the cutters.

JOHN H. HOWARD.

IUS

lift)

